Mucinex DM Maximum Strength Expectorant and Cough Suppressant breaks up excess mucus that causes chest congestion and controls cough. In fact, Mucinex DM is the only FDA-approved, 12 hour, extended-release guaifenesin with dextromethophan HBr. Mucinex DM is a safe and effective combition medicine that's available without a prescription. Uses: - Helps loosen phlegm (mucus) and thin bronchial secretions to rid the bronchial passageways of bothersome mucus and make coughs more productive. - Temporarily relieves cough due to minor throat and bronchial irritation as may occur with the common cold or inhaled irritants, the intensity of coughing, the impulse to cough to help you get to sleep. Active Ingredients (in each extended-release bi-layer tablet): -Dextromethorphan HBr 60 mg.. Cough supressant - Guaifenesin 1200 mg... Expectorant